Warning Method and Robot System

ABSTRACT

A method for warning a person in a working area about at least one first robot, and a robot system that includes the at least one first robot, wherein the movement of the robot in a future working interval is predicted, a determination is made as to whether a working area segment will be passed over by the robot in a first or second time period, a first or second visual warning is emitted in accordance with when the working area segment will be passed over, and the first or second visual warnings are respectively emitted onto a floor segment that is assigned to a respective working area segment.

The invention relates to robot system and a method for warning a person who is present in the region of the robot system while it is operating. In addition, the invention relates to a computer program which is suitable for operating a robot system in the sense of the inventive warning method.

From JP 2006/285635 A, an autonomous robot is known which is in a position to move itself along a path and in doing so to indicate to persons in the environment a section of the path traveled. For this purpose, lighting facilities are attached to the upper surface of the floor, these being coupled to receivers. The autonomous robot has a lighting controller which switches on the lighting facilities located in the floor, and thereby illuminates a section of the path travelled by the robot. Here, the lighting facilities arranged on the floor essentially form a chain.

WO 2009/0633181 A1 discloses a mobile robot which is designed to indicate by lighting devices danger areas which surround the robot. For this purpose, the robot is provided with projectors which are affixed to the robot's housing. The robot is designed to determine the outline of a danger area and by means of the projectors to create a correspondingly shaped projection on the floor. Here, a movement of the robot itself and a movement of a part of the robot, for example a robot arm, can be taken into account.

WO 2014/036549 A2 discloses a robot which is provided with a sensor system for detecting persons in a detection region around the robot. In addition, the robot incorporates a computational unit, which is designed to define a danger zone which at least partially overlaps the detection region. In addition, the robot is provided with an image recognition device, by means of which human body parts, such as for example a torso, head or arms, can be recognized. Depending on the body part of a human detected in the danger zone by the robot, various safety measures are initiated, such as for example a reduction in the travel speed of the robot.

From JP 05-229784, a warning system is known which comprises a colored laser source, which is designed to form a laser beam film on a surface. Here, the warning system in accordance with JP 05-229784 is affixed to a crane which is moving a transport item on its crane hook. The laser warning system is affixed to the crane in such a way that the danger area underneath the transport item is marked visibly.

A significant disadvantage of the warning systems known from the prior art consists in the fact that, during operation, close approaches frequently arise between robots and persons, in which accidents can only be avoided by the intervention of safety mechanisms of the robot. In this situation, the robot comes to a standstill, so that a delay occurs in the current work process.

The object underlying the invention is to make available a robot system and an associated warning method which overcomes the outlined disadvantages of the prior art.

The inventive method is used to warn a person about at least one first robot that is located in a working space. The working space is subdivided into a plurality of working space segments, where a floor segment is assigned to a working space segment. In the inventive method, a first step is carried out, in which a robot movement of the at least one robot is predicted. Here, the prediction can be effected by means of a time-shifted simulation or a code analysis of a control program of the at least one robot. In the first step, the robot movement is here predicted for a working interval. The working interval is a selectable period of time which extends by a selectable duration into the future. In a second method step, a determination is made of the space through which the at least one robot passes during the working interval in the course of the robot movement. Here, the space passed through, which is determined in the second step, comprises an area which is passed through by the main body of the robot and/or a robot arm and/or a manipulator affixed to the robot.

In a third method step, at least one working space segment which lies at least partially in the space passed through by the robot is determined. In doing so, it is also determined in each case whether this passing through takes place in a first and/or a second time period. The working interval in which the predicted robot movement takes place comprises the first and second time period. The first time period is preferably a time interval from 0 to 10 seconds in the future, the second time period preferably a time period from 10 to 20 seconds in the future. The third method step permits a prediction of when there will be a danger situation for an operator, and in which working space segments, while a program is being executed in accordance with the requirements in a working interval of the at least one first robot. If it is determined, on the basis of the method steps cited above, that a working space segment will be passed through by the robot within the first time period, then a first visual warning will be output on the floor segment which is assigned to the working space segment concerned. If it is determined, on the basis of the method steps cited above, that a working space segment will be passed through by the robot within the second time period, then a second visual warning will be output on its assigned floor segment.

In making the prediction of the robot movement, the inventive method may rely on a time-shifted simulation or a code analysis of the programming of the robot. A time-shifted simulation or a code analysis of a robot's programming can be rapidly and reliably carried out in a technically simple manner with low requirements for computational capacity. In doing so, it is possible rapidly to convert unpredictable external events, such as for example a halting or delay of the robot which has occurred in the meantime, into an updated output of visual warnings. A robot's programming essentially comprises the sequential working through of movement commands, whereby the predictability of a robot's movement is further simplified.

The inventive method permits a differentiated image of a potential future danger situation to be determined in a meaningful way. This makes it simpler for the robot movement which is to be carried out to be anticipated by persons, who can then adjust their behavior accordingly. By this means, it is possible to prevent in a simple way a close approach of a person to the at least one first robot, so that delays in the operational sequence of the at least one first robot are minimized.

In a preferred form of embodiment of the inventive method, account is taken not only of the at least one first robot but also of a first transport item which is being moved by the at least one first robot. By this, a space is detected which is passed through jointly by at least one first robot and the first transport item. It is hereby possible, by means of the inventive method, to determine more precisely the space traveled through in which there is a danger situation for a person. The claimed method is thereby more differentiated in the determination of an existing situation and permits a more informative warning behavior with respect to a person, whereby the safety prevailing in the working space is improved.

In a further preferred form of embodiment of the inventive method, the first and the second visual warning are each embodied as colored signals or as light patterns. In doing this, the first and second visual warnings can for example be embodied as constant or periodic light signals in different colors. It is equally possible that each of the first and second visual warnings forms geometric shapes, which are embodied on the relevant floor segment, such as for example a pattern of points, geometric figures or symbols. In this case, the light patterns can be constant over time or changeable. The term changeable light pattern is to be understood, for example, as an animation. By this means, the inventive method can output a further differentiated warning to a person, which because of its obvious meaningfulness supplies in a simple way a precise image about a potential danger situation.

Over and above this, the inventive method can determine in addition whether there is, in at least one third time period, a working space segment which lies at least partially within the space traveled through. If it is determined that, within the at least one third time period, a working space is traveled through, a third visual warning is output on an associated floor segment. A warning method with consideration of a third time period which outputs a third visual warning permits a more differentiated determination and representation of the scope of the potential danger in a prevailing situation. By this means, the prevailing safety is further increased.

In a preferred form of embodiment of the inventive method it is possible, in a method step in which a first, second or third visual warning is output, to trigger in addition an acoustic warning. The triggering of an acoustic warning makes it possible to warn of situations with a high potential danger. It is thus possible, for example if there are in the working space exclusively working space segments which are traveled through by the at least one first robot in the first time interval, to warn of them by means of a warning tone. By this means, it is possible to avoid operating situations in which safety mechanisms of the at least one first robot intervene, and must give rise to a delay. This is particularly advantageous in the case of work sequences in which robots are used with a high travel speed.

In a further especially preferred form of embodiment of the inventive method, the visual warnings and/or the acoustic warning are embodied in addition as a function of at least one process parameter of the at least one robot. In doing this, a visual or acoustic warning is adapted with the intention that the warning is embodied in accordance with the intensity of the prevailing danger situation. For example, if a high potential danger is present, a changed tone of color can be selected, a visual warning can switch over from a constant to a periodic light signal, or an all-over visual warning to a light pattern.

In this case, a travel speed of the at least one robot can be the process parameter, as a function of which the visual warnings and/or the acoustic warning is/are adapted. When the robot's travel speed during the working interval is high, there is a greater potential danger than when the travel speed is low. Over and above this, it is also possible to apply as the process parameter qualitative information about the first transport item. Here, the qualitative information of the first transport item reflects whether, because of the physical or chemical properties of the first transport item, an increased danger can arise from it for a person. Transport items whose qualitative information can lead to a more intense or clearer warning, in the sense of the inventive method, could be for example containers with chemicals or molten material, pointed objects, items made of hard material, or items made of materials which are hard to perceive visually, such as for example glass or PMMA. Further, as process parameters, use can be made of information relating to the nature and/or scope of the safety measures of the at least one robot which would be triggered if the safety mechanisms of the at least one robot intervene. For example, if the intervention of the safety mechanisms leads to a standstill of a complete production line, the first and/or the second visual warning or an acoustic warning will be output with an increased intensity. If the intervention of the safety mechanisms leads to a delay with no further consequences, the first and/or the second visual warning or the acoustic warning will be output with a reduced intensity.

In one particularly preferred form of embodiment of the inventive method, a further step determines whether a working space segment will not be traveled through by at least one first robot during the working interval. In this case, a visual all-clear signal will be output in the associated floor segment, signaling to a person that during the working interval there will be no danger situations present in the working space segment concerned. This communicates to the person in the working space in a meaningful manner which regions of the working space can be accessed without further consideration, without the need to allow for a standstill or delay of the at least one first robot. By this means, the efficiency of the inventive method is further improved.

Further, the inventive method can be developed in such a way that the method steps, in which a robot movement in a working interval is predicted, the space traveled through during the working interval is determined, and it is determined whether a working space segment lies at least partially in the space traveled through in a first and a second time period, is also carried out for at least one second robot. Here, a robot movement of the second robot is predicted separately in a working interval, and the space traveled through by the second robot is determined. It is also separately determined whether a working space segment lies at least in the space traveled through within the first and second time period. The steps to predict the robot movement, to determine the space traveled through, and to determine the working space segments which lie at least partially in the space traveled through, are here carried out simultaneously with the corresponding method steps in respect of the at least one first robot. The working interval considered is identical in each case for the first and the second robot, as are the first and second time periods for each of which it is detected whether at least one working space segment lies at least partially in the space traveled through. By this means, any potential danger which is present is detected in a cohesive manner for a working space with a plurality of robots and is displayed as part of a coherent warning image, which comprises a plurality of first and second visual warnings. This enables a person who is present in a region with a plurality of robots to assess a complex situation which exists in a rapid and simple manner, and thus to avoid danger situations in which safety mechanisms of at least one robot intervene, and can thereby avoid delays in the working sequence. The inventive method improves the safety in a working space, and at the same time raises the productivity which can be achieved by the robots located within it.

The invention relates in addition to a robot system which comprises a control unit and at least one first robot, which is arranged in a working space and is linked to the control unit. A link between the at least one first robot and the control unit can here be any form of data link, via which signals can be exchanged between the at least one first robot and the control unit. The working space in which the at least one first robot is arranged here comprises a plurality of working space segments which subdivide the working space into appropriately many regions. Here, each working space segment comprises a floor segment, the contours of which correspond to the shape of the working space segment. The inventive robot system comprises in addition at least one lighting element, which is linked to the control unit. The link between the at least one lighting element and the control unit can be any form of link which permits the communication of a control command from the control unit to the at least one lighting element. In particular, the link can be constructed as a data cable or a radio link. The at least one lighting element is designed to output a visual warning onto at least one floor segment in each case. The control unit of the inventive robot system is, furthermore, in a position to carry out a method, which comprises the features of the inventive warning method, for warning a person about the at least one first robot. The inventive robot system permits a complex work sequence to be carried out at increased speed in a working space, whereby a high level of safety is provided for persons who are present and move in the working space. At the same time, a high level of productivity is provided in that standstill periods and delays of the at least one first robot are minimized.

In one preferred form of embodiment of the inventive robot system, it comprises at least one second robot. Such a form of embodiment allows the placing in a small space of a plurality of robots, which can be operated at high speed and are in a position to implement even complex production sequences. The complex danger situation which then arises due to the interaction of the at least two robots can be simply recognized by a person, so that a close and safe network of humans and robots is possible. The invention allows the productivity which can be achieved with a robot system to be further raised. In a preferred form of embodiment of the invention, the at least one lighting element can be embodied as a plurality of light segments, which can be mounted in various shapes and arrangements. A light segment is assigned to a particular floor segment, and is designed in each case to output a visual warning on the associated floor segment. A light segment can here be affixed either directly onto the associated floor segment or above the associated floor segment. A particularly preferred form of embodiment comprises a lighting element which is affixed to the ceiling. In an alternative form of embodiment of the inventive robot system, the at least one lighting element can be constructed as a controllable image projector, which is affixed above the associated floor segments. A controllable image projector allows a visual warning to be directed onto a plurality of floor segments using a small number of system components. By this means, the complexity of the system is reduced, and the reliability of the robot system is further raised. Over and above this, with a controllable image projector it is possible to change its programming in a simple way, so that visual warnings can easily be adapted to different application purposes. Further, with a controllable image projector it is possible to project a constant or time-varying light pattern onto a floor segment. The inventive robot system can thereby be rapidly and efficiently adapted to a plurality of configurations in the working space, and a plurality of meaningful visual warnings can be generated.

The invention relates in addition to a computer program which is stored on a data storage medium and is suitable for implementing a warning method in accordance with the invention in a robot system in accordance with the invention. Here, the computer program is preferably stored in a memory of the control unit of the robot system, which captures the data from the at least one robot and undertakes the actuation of the at least one lighting element.

Further forms of embodiment and advantages of the invention are reproduced below in FIGS. 1 to 5.

These show:

FIG. 1 a schematic plan view of a first form of embodiment of the inventive robot system,

FIG. 2 a flow diagram of one form of embodiment of the inventive method,

FIG. 3 a time sequence of a further form of embodiment of the inventive method,

FIG. 4 a schematic plan view of a second form of embodiment of the inventive robot system,

FIG. 5 a schematic structure of a third form of embodiment of the inventive robot system.

FIG. 1 shows a robot system 80 with a first robot 10 which has a movable manipulator and is arranged in a working space 20. In the region of the working space 20, a first transport item 15 and a second transport item 17 are guided along a direction of conveyance 13 to the first robot 10. The first robot 10 is embodied to grip one piece each of the transport items 15, 17 using the manipulator 12, and to advance them with a pivoting movement to a deposit point 23. Here the first robot 10 and the deposit point 23 are affixed in the working space 20. The working space 20 is subdivided into a plurality of essentially rectangular working segments 24, which border each other along dividing lines 28. The working segments 24 are essentially, but not shown in more detail, cuboidal spatial segments which in each case are bounded on a lower side by the floor 22 of the working space. There is a corresponding floor segment 26 belonging to each working space segment 24, wherein the floor segments 26 also border each other along the imaginary dividing lines 28. In addition to this, each of the floor segments 26 is provided with a lighting element 30, which is embodied as light segments. Each of the light segments 32 is embodied to output by means of lighting a visual warning on the surface of a floor segment 26.

FIG. 1 shows in addition a person P who is moving along a path 27 in the working space 20. In FIG. 1, shown by an arrow, is a robot's movement 18 which is to be made by the first robot 10 in a working interval 50, which is not shown in more detail. The direction of the arrow here represents the time sequence of the robot's movement. In doing this, the first robot 10 travels through a space 19 which has an essentially circular arc-shaped form. In total, the space 19 which is traveled through intersects a plurality of working space segments 24, and passes over their associated floor segments 26. Also represented in FIG. 1 is a working space segment 24 with its associated floor segment 26′ which, in the course of the robot's movement 18, the first robot travels through before a second working segment 24″ and its associated floor segment 26″. The first floor segment 26′ is passed over by the first robot 10 in a first time period 26, not shown in FIG. 1, so that a first visual warning 62 is output on the first floor segment 26. The second floor segment 26″ is not passed over by the first robot 10 until a later second time period 54, not shown, so that a second visual warning 64 is output on the second floor segment 26″ via a lighting element 30. The working space 20 has in addition working space segments 24 which the first robot 10 does not travel through in the working interval 50. In these working space segments 24 there is no danger situation for the person P. so that an all-clear signal 69 is output on the associated floor segments 26. The different visual warnings 62, 64 together with the all-clear signal 69 indicate to the person P what potential danger there is in which region of the working space 20.

FIG. 2 shows a schematic flow diagram of the inventive method. In a first step 110, a prediction is made of a robot's movement 18 which is to be made by the at least one first robot 10 in a working interval 50. Here, on the basis of the programming of the at least one first robot 10, its planned movement sequence is predicted on the assumption that no events will occur during it which lead to a standstill or a delay of the at least one first robot 10. In a further method step 120, a determination is made of which space will be traveled through by at least one first robot 20 in the working interval 50 which is being analyzed. In a further method step 130, a determination is made of whether a working space segment 24 lies at least partially within the space 19 traveled through. A working space segment 24 which is traveled through by at least one first robot 10 during the working interval 50 is then initially identified as a potential danger region for a person P. In addition, it is determined in the method step 130 whether a corresponding working space segment 24 is traveled through by the at least one first robot 10 in a first or second time period 52, 54. A working space segment 24 which is traveled through in an earlier time period than a working space segment in a later time period is here classified as more dangerous.

Depending on the result of the method step 130, either the fourth method step 140 or the fifth method step 150 takes place for a working space segment 24. If it is determined in the preceding determination step 130 that during the first time period 52 the working space segment 24 lies at least partially in the space 19 traveled through by the robot 10, then a first visual warning 52 is output on the associated floor segment 26. If it is determined in the preceding method step that during the second time period 54 the working space segment 24 lies at least partially in the space 19 traveled through, then a second visual warning 64 is output on the associated floor segment 26.

From FIG. 3, the timing sequence of a further form of embodiment of the inventive method will be apparent. The starting point is the start time point 51, which defines the beginning of the working interval 50. In FIG. 3, a first time period starts, again beginning essentially at the start time point 51. If it is determined during the method steps 110, 120, 130, not shown in more detail, that a working space segment 24, again not shown, will be traveled through within the first time period 52 then, as part of the fourth method step 140, a first visual warning 62 will be output on the associated floor segment 26. Following on from the first time period 52 is a second time period 54. If a working space segment 24 will be traveled through during the second time period 54 then, as part of the fifth method step 150, a second visual warning 64 is output. Here, the second time period 54 lies within the range of the working interval 50. The second time period 54 is followed by a third time period 56, which essentially also ends at the end of the working interval 50. If a working space segment 24 will be traveled through during the third time period 56 then a third visual warning 66 is output on the associated floor segment 26. FIG. 3 further discloses an additional time period 59, which lies after the end of the working interval 50. If a working space segment 24 is not traveled through up until the beginning of the additional period 59, an all-clear signal 69 is output on the associated floor segment 26. The arrow 57 represents the time sequence, so that the working interval 50, together with the time periods 52, 54, 59, are always time periods which are to be understood as being seen relative to a start time point 51. Hence, during the operational sequences of the associated robot system 80 along the arrow 57, the time periods 52, 54, 56, 59 accompany it. The method shown in FIG. 3 is performed with continual repetition of the individual method steps 110, 120, 130, 140, and 150.

FIG. 4 shows a further form of embodiment of the inventive robot system 80 in the working space 20. In the region of the working space 20, a first transport item 15 and a second transport item 17 are fed along a direction of feed 13 to the first robot 10. The first robot 10 is embodied for the purpose of using the manipulator 12 to grip one piece each of the transport items 15, 17, and with a pivoting movement to advance them to the deposit position 23. Here, the first robot 10 and the deposit position 23 are affixed in the working space 20. The working space 20 is subdivided into a plurality of essentially rectangular working segments 24, which border each other along dividing lines 28. Here, the working segments 24 are essentially, cuboidal-shaped spatial segments, not shown in more detailed, each of which is bounded on its lower side by the floor 22 of the working space. Belonging to each working space segment 24 is a floor segment 26, where the floor segments 26 also border each other along the imaginary dividing lines 28. Over and above this, each of the floor segments 26 is provided with a lighting element 30, which is constructed as a light segment. Each of the light segments 32 is embodied to output a visual warning onto the surface of a floor segment 26 by means of lighting.

FIG. 4 shows in addition a second robot 11, which provides a manipulator 12 and carries out a work step in the region of the deposit point 23. The first and second robots 10, 11 each carries out movements 18 at the same time, in each of which a space 19 is traveled through. Here, the working space segments 24 lie at least partially in the space 19 traveled through, which is assigned to the robots 10, 11. The direction of the movements 18 is made clear in each case in FIG. 4 by an arrow. The direction of the arrow corresponds to the execution over time of the movement 18 concerned in the working interval 50, not shown. The working space segment 24′″ in the region of the deposit point 23 is traveled through by both robots during the working interval 50. The first robot 10 travels through the working space segment 24′″ at the end of its movement 18 in the second time period 54, which is again not shown. In addition, the working space segment 24′″ by the second robot 11 at the start of the working interval 50, and hence in the first time period 52. On the basis of the inventive method, the robot system 80 recognizes that in the first time period 52 there is already a potential danger in the working space segment 24′″, and outputs the first visual warning 62 in the associated floor segment 26′″. Here, the first visual warning is output by means of the lighting element 30, which is constructed as a light segment.

For the remaining working space segments 24, which also lie at least partially in the space 19 which is traveled through, it is again determined, on the basis of the inventive method, whether there is a potential danger in the first or second time period 52, 54, and a corresponding first or second visual warning 62, 64 is output. In the case of working space segments 24 which are not traveled through by the robots 10, 11, an all-clear signal 69 is output.

FIG. 5 shows schematically the structure of the inventive robot system 80, which comprises two robots 10, 11. Each of the robots 10, 11 provides a manipulator 12, which is driven by an actuator 16. The robots 10, 11 are, in addition, equipped with a sensor system 14 which permits, for example, the presence of a person to be recognized and the associated data to be passed on to the controller of the robots 10, 11. The robots 10, 11 are arranged in the working space 20 for the performance of working steps on the first and second transport items 15, 17. Each of the transport items 15, 17 has qualitative data 72, which can be detected by the sensor system 14 of the robots 10, 11. The robots 10, 11 are in a position to forward to a control unit 40 the qualitative data 72 which is detected, via a link 42. Apart from the qualitative data 72, other process parameters 70, such as for example the movement speed of a robot 10, 11, are also forwarded via the link 42 to the control unit 40. The link 42 is suitable for transporting data and is constructed as a data cable 44 between the first robot 10 and the control unit 40. The second robot 11 is coupled to the control unit 40 via a link 42 which is embodied in the form of a radio link.

Additionally, FIG. 5 shows schematically a plurality of floor segments 26, each of which is assigned to a working space segment 24, not shown in more detail. The floor segments 26 are provided with light segments 32, which serve as a lighting facility 30. An individual light segment 32 is suitable for bringing up a visual warning 62, 64, 66 or an all-clear signal 69 on at least one floor segment 26. A floor segment 26 is coupled to the control unit 40 via a radio link 46. The remaining floor segments 36 are linked to the control unit 40 via data cables 44, which serve as the link 42. The control unit 40 is, in addition, coupled via the data cable 44 to a controllable image projector 34, which is in the form of a beamer, which is also in a position to output a visual warning 62, 64, 66 on the floor segments 26. Further, the controllable image projector 34 is suitable for bringing up on floor facility 30 a visual warning 62, 64, 66 or an all-clear signal 69. The controllable image projector 34 can be actuated by the control unit 40 in such a way that, as the visual warning 62, 64, 66 or the all-clear signal 69, a constant or time-varying light pattern is output. The visual warning 62, 64, 66 is here able to take on different colors, can incorporate color transitions or be in the form of static or animated symbols. The robot system 80 is also provided with an audible warning signal emitter 36, which is linked via the data cable 44 to the control unit 40 and is suitable for outputting to a person in a working space 20 an additional audible warning in situations with a heightened potential danger. The control unit 40 has a memory in which is stored in executable form a computer program 90 which implements the inventive method in the robot system 80. The computer program 90 is embodied in such a way that it can process and evaluate as part of the inventive method all the data, such as for example process parameters 70, detected by robots 10, 11 and sent via the link 42, by data cable 44 or radio link 46. The computer program 90 is also suited to sending control signals to the individual lighting facilities 30, the controllable image projector 34, or to the audible warning signal emitter 36, said control signals bringing up the appropriate visual warnings 62, 64, 66, audible warnings 68 and the all-clear signal 69. 

1.-14. (canceled)
 15. A method for providing a warning to a person about at least one first robot in a working space comprising a plurality of floor segments, a working space segment being assigned to each floor segment of the plurality of floor segments, the method comprising: a) predicting a robot movement which is performed by the at least one first robot in a working interval; b) determining a space through which the at least one first robot travels during the working interval; c) determining at least one working space segment which, within a first and a second time period, resides at least partially within the space through which the at least one first robot traveled; d) outputting a first visual warning onto a floor segment if the at least one first robot will travel through an associated working space segment within the first time period; and e) outputting a second visual warning onto the floor segment if the at least one first robot will travel through the associated working space segment within the second time period.
 16. The method as claimed in claim 15, wherein during step b) a space simultaneously traveled through by the at least one first robot and a first transport item is detected.
 17. The method as claimed in claim 15, wherein the first and second visual warnings each comprise a colored signal or light pattern.
 18. The method as claimed in claim 16, wherein the first and second visual warnings each comprise a colored signal or light pattern.
 19. The method as claimed in claim 15, wherein step c) is also performed for at least one third time period and within at least one further step f) a third visual warning is output onto the floor segment if the associated working space segment is traveled through.
 20. The method as claimed in claim 15, wherein during steps d) to f) an audible warning is additionally output.
 21. The method as claimed in one of claim 15, wherein at least one of (i) visual warnings and (ii) an audible warning form a function of at least one process parameter of the at least one first robot.
 22. The method as claimed in claim 20, wherein the at least one process parameter comprises at least one of (i) a movement speed of the at least one first robot and (ii) an item of qualitative data for a first or a second transport item.
 23. The method as claimed in claim 19, further comprising: outputting a visual all-clear signal in each floor segment if the at least one first robot fails to travel through the associated working space segment during the working interval.
 24. The method as claimed in claim 15, wherein steps a) to c) are additionally performed for at least one second robot.
 25. A robot system comprising: a controller; at least one first robot linked to the control unit and arranged in a working space comprising a plurality of working space segments each having an assigned floor segment; and at least one lighting element linked to the control unit and is configured to output in each case on at least one floor segment a visual warning; wherein the controller is configured to: a) predict a robot movement which is performed by the at least one first robot in a working interval; b) determine a space through which the at least one first robot travels during the working interval; c) determine at least one working space segment which, within a first and a second time period, resides at least partially within the space through which the at least one first robot traveled; d) output a first visual warning onto a floor segment if the at least one first robot will travel through an associated working space segment within the first time period; and e) outputting a second visual warning onto the floor segment if the at least one first robot will travel through the associated working space segment within the second time period.
 26. The robot system as claimed in claim 25, further comprising: at least one second robot.
 27. The robot system as claimed in claim 25, wherein the at least one lighting element comprises a plurality of light segments, each of said plurality of light segments being affixed on or above an associated floor segment.
 28. The robot system as claimed in claim 26, wherein the at least one lighting element comprises a plurality of light segments, each of said plurality of light segments being affixed on or above an associated floor segment.
 29. The robot system as claimed in claim 26, wherein the at least one lighting element comprises a controllable image projector arranged above associated floor segments.
 30. The robot system as claimed in claim 27, wherein that the at least one lighting element comprises a controllable image projector arranged above associated floor segments.
 31. A non-transitory computer readable storage medium encoded with a computer program which, when executed by a processor of a controller, provides a warning to a person about at least one first robot in a working space comprising a plurality of floor segments, a working space segment being assigned to each floor segment of the plurality of floor segments, the computer program comprising: a) program code for predicting a robot movement which is performed by the at least one first robot in a working interval; b) program code for determining a space through which the at least one first robot travels during the working interval; c) program code for determining at least one working space segment which, within a first and a second time period, resides at least partially within the space through which the at least one first robot traveled; d) program code for outputting a first visual warning onto a floor segment if the at least one first robot will travel through an associated working space segment within the first time period; and e) program code for outputting a second visual warning onto the floor segment if the at least one first robot will travel through the associated working space segment within the second time period.
 32. The non-transitory computer readable storage medium of claim 31, wherein the non-transitory computer readable storage medium comprises a memory or data carrier. 